The invention concerns a piston for internal combustion engines, in particular for passenger automobiles. The piston being of the type having a ring carrier held in a piston body so as to accommodate piston rings associated with the piston.
In the effort at constant reduction of the frictional losses and strains on the driving mechanism generated in the piston drive of internal combustion engines, attempts have been made at rendering as small as possible the piston masses and the surfaces for transmission to the surrounding cylinder walls of the transverse forces effective in the piston. However, heretofore it has not been possible to reduce the piston skirt surface as desired inasmuch as thereby operational safety was impaired. Due to the large thermal expansions in the region of the ring field as well as the lack of lubricant prevailing there, the piston lands could not be utilized for transmission of the lateral supporting forces of the piston to the cylinder wall. Rather, sufficiently large piston skirt surfaces below the piston lands had to be provided which increased the entire piston skirt length and the piston mass. Even in cases in which the piston rings are arranged in separate ring carriers held by the piston basic body, the conditions are basically the same since the known ring carriers are merely composed of special wear-resistance steel materials while the piston basic body is composed, e.g., of a light metal alloy.